Make sure the account you would like to change is selected and click "Continue".

Select "Spam Filtering".

Select the desired retention period in the box labeled "Spam retention (delete after X days):" and click "Update Spam Filtering".

Unlike our old email service where messages were deleted from the "Junk" folder once a night, there is an ongoing process that determines if messages are older than the specified retention period and messages are being deleted throughout the day. The time when the messages are purged from the system is not predictable.